US7197380B2  System for controlling the stability of a vehicle using an algorithm comparing average slopes of variation of a parameter  Google Patents
System for controlling the stability of a vehicle using an algorithm comparing average slopes of variation of a parameter Download PDFInfo
 Publication number
 US7197380B2 US7197380B2 US11039108 US3910805A US7197380B2 US 7197380 B2 US7197380 B2 US 7197380B2 US 11039108 US11039108 US 11039108 US 3910805 A US3910805 A US 3910805A US 7197380 B2 US7197380 B2 US 7197380B2
 Authority
 US
 Grant status
 Grant
 Patent type
 Prior art keywords
 μ
 tire
 curve
 α
 variation
 Prior art date
 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
 Expired  Fee Related, expires
Links
Images
Classifications

 B—PERFORMING OPERATIONS; TRANSPORTING
 B60—VEHICLES IN GENERAL
 B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
 B60T8/00—Arrangements for adjusting wheelbraking force to meet varying vehicular or groundsurface conditions, e.g. limiting or varying distribution of braking force
 B60T8/17—Using electrical or electronic regulation means to control braking
 B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
 B60T8/17551—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters

 B—PERFORMING OPERATIONS; TRANSPORTING
 B60—VEHICLES IN GENERAL
 B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
 B60T2270/00—Further aspects of brake control systems not otherwise provided for
 B60T2270/40—Failsafe aspects of brake control systems
 B60T2270/406—Testmode; Selfdiagnosis
Abstract
Description
This application claims benefit of French Application Patent No. 04/00423, filed Jan. 16, 2004, and French Application Patent No. 04/00424, filed Jan. 16, 2004, both of which are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to vehicle stability control systems. In a particular application, the invention relates to systems aimed at preventing the locking of the wheels during hard braking, popularized by the term “ABS”. More generally, the invention concerns all systems aimed at maintaining the vehicle on a stable path by acting automatically on actuators such as those determining a wheel driving or braking torque, or those determining the steering of one or more wheels, or even those concerning the suspension, where it is known that this also has an effect on the control of the path (for example active antiroll). In the particular application mentioned above, the actuators are the brakes on a wheel or the device imposing a driving torque on a wheel.
The present invention also relates to methods of testing tires.
2. Description of Related Art
For information, the longitudinal coefficient of friction μ of the tire is the quotient of the longitudinal force divided by the vertical force applied, that is to say the load applied on the tire (in the simplified case of a pure braking force, and a person skilled in the art will easily know how to apply this more generally); the slip G on the tire is G=0% when there is no slip between the speed of the tire and the speed of the vehicle, that is to say if the tire is rolling freely, and G=100% if the tire is locked rotationally. Typically, according to the environment (the nature of the ground (asphalt, concrete), dry or wet (height of water), temperature and level of wear on the tire), the value of μ as a function of the slip G and the nature of the ground may vary enormously (μ_{max }equals approximately 0.15 on ice and approximately 1.2 on dry ground).
It is known that the braking of the vehicle will be all the more effective when it is managed to make the tread function at a slip G corresponding to the maximum value of the coefficient of friction (sometimes also referred to as the coefficient of adherence). The maximum value of the coefficient of friction is termed μ_{max}. However, the average driver is not capable of tuning out the braking so as to satisfy this condition.
This is why vehicle stability control systems have been developed, automatically modulating the braking force so as to aim at a predetermined slip target, and deemed to correspond to the maximum of the coefficient of friction.
In particular, U.S. Patent Application Publication. No. 2004/0032165 A1, published Feb. 19, 2004, and which is incorporated herein by reference in its entirety, proposes a method of regulating the slip using a quantity called the “Invariant”, which the research of the inventors made possible to discover, this quantity being called like this because it is substantially constant whatever the tire in question and whatever the adhesion of the ground on which the tire is rolling.
Also, through U.S. Patent Application Publication. No. 2004/0024514, published Feb. 5, 2004, and which is incorporated herein in its entirety, a method of regulating slip using the same quantity called the “Invariant”, has been proposed. Though this method makes it possible to determine a slip target which is actually much closer to the real maximum coefficient of friction of the tire under actual rolling conditions, there do however exist cases where it is possible to determine an even better target for improving the effectiveness of the braking (or of the acceleration).
The invention proposes an algorithm termed the “Average” algorithm for predicting an ideal target for a parameter whose control is provided in a vehicle stability control system or in a method for testing a tire.
In a general formulation, the invention proposes a vehicle stability control system in which a characteristic parameter Q of the functioning of a tire of the vehicle intended to roll on the ground varies as a function of a parameter P according to a particular law, an optimum value of the parameter P being imposed by a controller directly or indirectly so as to act on at least one of the elements chosen from the group comprising the rotation torque applied to the tire, the steering angle of the tire, the camber angle of the tire and the vertical force applied to the tire, in which the controller comprises means for:
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (P_{i}, Q_{i}), so as to model a first variation curve Q_{i}=f(P_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (Q_{i}, P_{i}), in which Q_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (Q_{i}, P_{i}), so as to model a second variation curve Q_{i}=f(P_{i}, B_{[avg/p]}) including the pair or pairs (Q_{i}, P_{i}), in which Q_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (P_{i}, Q_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip P^{Cavg }using at least the last pair of values (P_{i}, Q_{i}).
The result sought is to maintain the value of a parameter Q at a value chosen as being ideal in the situation of the vehicle at the time. In the present document, a detailed description is given of an application to the control of the slip of a tire, typically during a braking maneuver or during a maneuver acting on the yawing of a vehicle (a function known by the term ABS in the first case or a function known by the name ESP in the second case). Finally, an application is mentioned aimed at controlling the path using actuators other than those acting on the torque at the wheels.
In a first application, the invention therefore proposes a vehicle stability control system in which the parameter P is the slip G on the tire and the characteristic parameter Q is the coefficient of friction μ of the tire, the system comprising means for imparting a longitudinal force to the tire, means of modulating the longitudinal force and means for calculating the slip parameter G^{Opt }at each activation of the means for imparting a longitudinal force to the tire in the following manner:
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_{i}, G_{i}), so as to model a first variation curve μ_{i}=f(G_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (μ_{i}, G_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_{i}, G_{i}), so as to model a second variation curve μ_{i}=f(G_{i}, B_{[avg/p]}) including the pair or pairs (μ_{i}, G_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (G_{i}, μ_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip G^{Cavg }using at least the last pair of values (G_{i}, μ_{i}).
The application of choice of the present invention lies in the control of the slipping of a wheel in braking, for the purpose of making the tire function at the level where the coefficient of friction is at a maximum. The entire following description in this case concerns a device for modulating the longitudinal force which acts on the braking control. It should be indicated once and for all that, in this case, the operations indicated above, and in more detail below, are initialized (i=0) at each start of a braking maneuver. However, if it is decided to apply the present invention to the control of the slipping of a wheel in acceleration, the device modulating the longitudinal force acts on the driving torque at the wheels and the operations indicated at each request for a variation in the driving torque greater than a predetermined torque threshold are initialized (i=0).
It should also be noted that, in the context of the present invention, it is of little importance whether the tread whose adhesion characteristic is processed is that of a pneumatic tire or a nonpneumatic elastic solid tire or a track. The terms “tread”, “tire” or “pneumatic tire”, “solid tire”, “elastic tire”, “track” or even “wheel” must be interpreted as equivalent. It should also be noted that the determination of the values of the coefficient of friction μ_{i }for each slip G_{i }may be carried out by direct measurement or by estimation from other measurements or from the estimation of other quantities such as the force in the plane of the ground and the vertical load.
Similarly, in another aspect of the invention, the invention proposes a tire testing system in which a characteristic parameter Q of the functioning of a tire intended to roll on the ground varies as a function of a parameter P according to a particular law, an optimum value of the parameter P being imposed by a controller directly or indirectly so as to act on at least one of the elements chosen from the group comprising the rotation torque applied to the tire, the steering angle of the tire, the camber angle of the tire and the vertical force applied to the tire, in which the controller comprises means for:
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (P_{i}, Q_{i}), so as to model a first variation curve Q_{i}=f(P_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (Q_{i}, P_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (Q_{i}, P_{i}), so as to model a second variation curve Q_{i}=f(P_{i}, B_{[avg/p]}) including the pair or pairs (Q_{i}, P_{i}), in which Q_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (P_{i}, Q_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip P^{Cavg }using at least the last pair of values (P_{i}, Q_{i}).
The result sought is to maintain the value of a parameter Q at a value chosen according to the objective of the test. In the present document, an application to the control of the slip of a tire, typically during a braking maneuver, is described in detail. Finally, an application is mentioned aimed at controlling the drift of the tire.
In the first case, the parameter P is the slip G of the tire and the characteristic parameter Q is the coefficient of friction μ of the tire, the invention proposing a tire test system using means for imparting a longitudinal force to a tire intended to roll on the ground, means of modulating the longitudinal force using at least one “target slip” parameter which is the slip aimed at in the rotation of the tire on the ground, and means for calculating the parameter G^{Opt }at each activation of the means for imparting a longitudinal force to the tire, for successive levels “i” of the longitudinal force each corresponding to a slip G_{i}, in the following manner:
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_{i}, G_{i}), so as to model a first variation curve μ_{i}=f(G_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (μ_{i}, G_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (μ_{i}, G_{i}), so as to model a second variation curve μ_{i}=f(G_{i}, B_{[avg/p]}) including the pair or pairs (μ_{i}, G_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (G_{i}, μ_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip G^{Cavg }using at least the last pair of values (G_{i}, μ_{i}).
The application of choice of the present invention lies in the control of the slipping of a wheel in braking on a machine or test vehicle. The entire following description in this case concerns a device for modulating the longitudinal force which acts on the braking control. It should be indicated once and for all that, in this case, the operations indicated above, and in more detail below, are initialized (i=0) at each start of a braking maneuver. However, if it is decided to apply the present invention to the control of the slipping of a wheel in acceleration, the device modulating the longitudinal force acts on the driving torque at the wheels and the operations indicated at each request for a variation in the driving torque greater than a predetermined torque threshold are initialized (i=0).
The following figures show:
The “Average” algorithm consists of detecting the change in the curvature of the curve μ(G). It will be understood in fact that such a change reveals the proximity of the maximum adhesion. For this, the measurements or estimations are processed of the slip and coefficient of friction values associated with two regressions, one of which aims to model a variation curve which necessarily passes through the origin and the other one of which aims to model a variation curve which does not necessarily pass through the origin, that is to say whose first point is left free.
Preferably, a second condition is added causing the determination of the target slip using at least the last pair of values (G_{i}, μ_{i}), the second condition being as soon as G_{i }exceeds a predetermined threshold, for example 15%.
The use of linear regressions is particularly indicated. In this case, the difference between two linear regressions is looked at, as illustrated in
the first variation curve, depicted by a dotted line in
the second variation curve, depicted in a dot and dash line in
Naturally, since it is a case of linear regressions, the indicators are directly the respective slopes α_{1 }and α_{2 }of each of the straight lines.
It has been determined experimentally that, in the case of modeling by straight lines (linear regressions), the predetermined slope threshold for the difference between α_{1 }and α_{2 }is preferably around 30%.
In the end, the target slip G^{Cavg }adopted can quite simply be equal to the last value G_{i}. As an alternative and more precisely, the target slip G^{Cavg}=β·μ^{MAX}/A^{AVG }is determined with β a finetuning parameter. When in the present document a finetuning parameter is spoken of, this means that, even if there exists for this parameter a value or a range of values representing a physical reality, it is possible in practice to use this parameter arbitrarily as a finetuning knob for the practical functioning of the system for controlling the stability of a vehicle. It can be added simply that the parameter β represents an analogy with the Invariant, which results for β in a value of approximately 1.04 to be compared with the value 0.58 for the Invariant.
Before continuing, a few corrections are proposed to the low slip and coefficient of friction values obtained at the very start of a braking maneuver. At the start of braking, it has been found that the curve μ(G) can have a strange behavior. The purpose of this first part of the algorithm is to correct this behavior. In
The first part of the processing of the data will therefore consist of calculating the value of the slip from which it is possible to use the data for reliably calculating a target slip or the optimum slip. Let this slip be called G_{0}.
Consequently the vehicle stability control system is preferably such that, before all the operations using the curve of variation of μ_{i }as a function of G_{i}, a correction is carried out of the start of the curve by eliminating the first real pairs (μ_{i}, G_{i}) as long as the variation in μ_{i }as a function of G_{i }is not substantially constant and seeking the slip G_{0 }associated with a zero coefficient of friction (this is of course not limiting) such that the pair (0, G_{0}) and the noneliminated pairs (μ_{i}, G_{i}) are substantially aligned, and using a curve starting from (0, G_{0}) and joining the noneliminated pairs (μ_{i}, G_{i}), so that, for any value of G_{i }greater than G_{0}, G_{i }is replaced by G_{i}−G_{0}.
For this, for example, an algorithm is used which comprises the following steps:
systematically eliminating all the slip values associated with a coefficient of friction of less than 0.01;
continuously calculating regressions of μ and G as a function of time, preferably exponential regressions having regard to the trend of the foot of the curve in the example illustrated by means of
μ=e ^{A} ^{ μ } ^{·(t−T} ^{ Start } ^{)+B} ^{ μ } , G=e ^{A} ^{ G } ^{·(t−T} ^{ Start } ^{)+B} ^{ G }
It can be considered that the acquired values represent reality when the estimated or measured coefficient of friction is greater than 0.1 or when the slip exceeds 4%.
Therefore, before all the operations using the curve of variation of μ_{i }as a function of G_{i}, a correction is carried out of the start of the curve by eliminating the first real pairs (μ_{i}, G_{i}) as long as the variation in μ_{i }as a function of G_{i }is not substantially constant and finding the slip G_{0 }associated with a zero coefficient of friction such that the pair (0, G_{0}) and the noneliminated pairs (μ_{i}, G_{i}) are substantially aligned, and using a curve starting from (0, G_{0}) and joining the noneliminated pairs (μ_{i}, G_{i}). Next, in all the algorithms used, for any value of G_{i }greater than G_{0}, G_{i }is replaced by G_{i}−G_{0}.
Up till now it has been assumed that values of β have been calculated or estimated. However, in certain cases, the method of obtaining the coefficient of friction (from the braking force itself estimated on the basis of the braking pressure having regard to the particular characteristics of each vehicle —or the braking system of a tire test bench—and from the speed of the wheel) does not give a satisfactory result (the curve μ(G) calculated is too flat or continuously ascending). It is known that this is not realistic. To correct this problem, a numerical correction of the μ calculated can be introduced. This correction is based on the rate of change of the slip as a function of time. This is because, if the speed of the wheel (and therefore the slip) takes off quickly, it is because the unstable zone of the curve μ(G) is involved. Therefore the curve μ(G) should decrease, which is taken advantage of as follows:
where “Acorr” is a finetuning coefficient and can be specific to each algorithm. For example, a good practical value has proved to be 0.2 for the “Average” algorithm.
It should be noted that, if the value of μ_{max }is in itself modified by this correction, all the algorithms used are based on the shape of the curve rather than its values. The reader is also referred to the aforementioned patent application (U.S. Patent Application Publication. No. 2004/0032165 A1) where the fact is brought out that the “Invariant” algorithm makes it possible to calculate a slip target without even calculating the exact value of the associated coefficient of friction, the latter being unnecessary to the correct functioning of the slip control of a vehicle wheel.
In the aforementioned patent applications, the possibility of other applications of the “Invariant” algorithm was demonstrated, for example to the analysis of the drift thrust developed by a pneumatic tire or elastic solid tire in an operating zone close to the saturation of the drift thrust. It is because of the similarity in the variation laws of these physical phenomena. In the same way, the present invention has broader applications than solely the control of the slip in a vehicle stability control system or than controlling the slip during a test on the tire. In order to close the subject, let us simply cite (without even this addition being limiting, as will have been understood) that the invention also applies to a vehicle stability control system aimed at predicting the value of the drift angle δ of a pneumatic tire where the lateral force (also referred to as the “drift thrust”) is at a maximum, and also that the invention applies to a tire testing system aimed at predicting the value of the drift angle δ of a pneumatic tire where the lateral force (also referred to as the “drift thrust”) is at a maximum. It is a case of predicting when the tire will reach its maximum and therefore will no longer be capable of maintaining the drift thrust, in order to be able to maintain the functioning of the tire at a predetermined value of the drift thrust F_{det}. In order to maintain the functioning of the tire at a predetermined value, it is therefore also useful to estimate a target for the drift angle by means of an “Average” algorithm.
In this case, the parameter P is the drift angle δ of the tire and the characteristic parameter Q is the drift thrust F^{det }of the tire. It is a case of predicting when the tire will reach its maximum and therefore will no longer be capable of meeting its prime function, which is to enable the vehicle to turn, in order to be able to maintain the functioning of the tire at a predetermined value of the drift thrust F^{det}, or to warn the driver. To maintain the functioning of the tire at a predetermined target value, it is possible to carry out, possibly automatically, preventive interventions for reducing the speed of the vehicle in order to avoid critical driving situations (if the vehicle is not running as the driver wishes, an accident may result therefrom). In order to carry out these actions advisedly, it is therefore also useful to estimate a target by means of an “Average” algorithm.
In the application to vehicle dynamic management systems, the invention oncerns a system comprising means for controlling a parameter “ξ” according to instructions entered by the driver of the vehicle on his control means and according to instructions delivered by a path controller, means of modulating the parameter “ξ” and means for calculating the angle of drift parameter δ^{Opt }whenever means are activated for entering the parameter “ξ” in the following manner:
each time the system for controlling the variation in ξ is activated, for at least two different levels “i” of drift angle, reading various values of F_{Yi }(measured or calculated), and the associated drift angle δ_{i }obtained by estimation or direct measurement,
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (F_{i}, δ_{i}), so as to model a first variation curve F_{i}=f(δ_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (F_{i}, δ_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (F_{i}, δ_{i}), so as to model a second variation curve F_{i}=f(δ_{i}, B_{[avg/p]}) including the pair or pairs (F_{i}, δ_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (δ_{i}, F_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip G^{Cavg }using at least the last pair of values (δ_{i}, F_{i}).
In the application for testing the tires, the invention concerns a system for the slip testing of a tire, using means for imparting a drift angle to a tire under test on the ground, the means being equipped with a system of controlling a parameter “ξ” according to instructions coming from a test control means, and according to instructions delivered by a controller aimed at maintaining the functioning of the tire at a predetermined value of the drift thrust F^{det}, the controller using at least one optimum value δ^{Opt }of the drift angle corresponding to the maximum value of the drift thrust F^{det}, the controller comprising means for performing the following operations:
each time the system for controlling the variation in ξ is activated, for at least two different levels “i” of drift angle, reading various values of F_{Yi}, and the associated drift angle δ_{i }obtained by estimation or direct measurement,
determining coefficients A_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (F_{i}, δ_{i}), so as to model a first variation curve F_{i}=f(δ_{i}, A_{[avg/p]}) necessarily including by convention the origin, and the pair or pairs (F_{i}, δ_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{1 }of the first variation curve,
determining coefficients B_{[avg/p]} by direct calculation or by an appropriate regression, from a sufficient number of pairs (F_{i}, δ_{i}), so as to model a first second variation curve F_{i}=f(δ_{i}, B_{[avg/p]}) including the pair or pairs (F_{i}, δ_{i}), in which μ_{i }is different from zero,
determining an indicator of the average slope α_{2 }of the second variation curve,
as long as the difference between α_{1 }and α_{2 }is less than a predetermined slope threshold, repeating the previous operations for each new acquisition of a pair of values (δ_{i}, F_{i}),
as soon as the difference between α_{1 }and α_{2 }exceeds the predetermined slope threshold, determining a target slip G^{Cavg }using at least the last pair of values (δ_{i}, F_{i}).
Claims (32)
Priority Applications (4)
Application Number  Priority Date  Filing Date  Title 

FR04/00423  20040116  
FR0400424A FR2865285A1 (en)  20040116  20040116  Vehicle`s tire slipping testing system, has controller determining target slip of tire when difference between average gradients of variation curves, modeled using slip and adherence coefficient, exceeds preset gradient threshold 
FR0400423A FR2865176A1 (en)  20040116  20040116  Control system of the stability of a vehicle using an algorithm comparing average slopes of variation of a parameter based on another. 
FR04/00424  20040116 
Publications (2)
Publication Number  Publication Date 

US20050187672A1 true US20050187672A1 (en)  20050825 
US7197380B2 true US7197380B2 (en)  20070327 
Family
ID=34863195
Family Applications (1)
Application Number  Title  Priority Date  Filing Date 

US11039108 Expired  Fee Related US7197380B2 (en)  20040116  20050118  System for controlling the stability of a vehicle using an algorithm comparing average slopes of variation of a parameter 
Country Status (3)
Country  Link 

US (1)  US7197380B2 (en) 
KR (1)  KR20050075717A (en) 
CN (1)  CN1640702A (en) 
Cited By (1)
Publication number  Priority date  Publication date  Assignee  Title 

US20070256484A1 (en) *  20041014  20071108  Etsujiro Imanishi  Tire Hil Simulator 
Families Citing this family (4)
Publication number  Priority date  Publication date  Assignee  Title 

US20060173603A1 (en) *  20050202  20060803  Mohan Sankar K  Slip loss reduction control system for improving driveline efficiency 
FR2909946B1 (en)  20061213  20100917  Michelin Soc Tech  Method of estimating a risk of bond default floor of a motor vehicle 
CN101841288B (en) *  20100319  20121010  同济大学  Motion control method for vehicleused electric motors based on electric current control 
CN104236929B (en) *  20140618  20170405  吉林大学  LONGITUDINAL slip test method for the tire longitudinal force offset cancellation 
Citations (33)
Publication number  Priority date  Publication date  Assignee  Title 

US3980346A (en)  19740710  19760914  Teldix Gmbh  Antilocking control system for simultaneous regulation of steered wheels or wheels on a diagonal of vehicle 
US4715662A (en)  19831216  19871229  Robert Bosch Gmbh  Method for determining an optimal slip value 
US4794538A (en)  19851008  19881227  Robert Bosch Gmbh  Method to control the operation of wheels of a vehicle to prevent slipping or skidding, and brake locking 
DE4030724A1 (en)  19900928  19920402  Bosch Gmbh Robert  Vehicular antilock control system using inverse hydraulics model 
DE4218034A1 (en)  19920602  19931209  Porsche Ag  Measuring frictional connection potential of motor vehicle  involves measuring and smoothing vehicle parameters, e.g. speed and acceleration, and deriving vehicle state and road conditions 
DE4329745C1 (en)  19930903  19940721  Volkswagen Ag  Vehicle aquaplaning or skidding detection method 
US5343918A (en)  19900517  19940906  The Goodyear Tire & Rubber Company  Tread for a pneumatic tire with differing tread stiffness regions 
US5402345A (en)  19900804  19950328  Robert Bosch Gmbh  Method for estimating speed of a braked vehicle 
DE4435448A1 (en)  19931013  19950420  Volkswagen Ag  Method for permanently determining the coefficient of adhesion of a carriageway 
US5409302A (en)  19921006  19950425  ThomsonCsf  Braking method and device, vehicle equipped with said device 
US5513907A (en)  19930622  19960507  Siemens Aktiengesellschaft  Method and circuit configuration for determining a frictional value 
EP0716948A2 (en)  19941214  19960619  Toyota Jidosha Kabushiki Kaisha  Dynamic behavior estimate system of automotive vehicle 
EP0829401A2 (en)  19960913  19980318  Volkswagen Aktiengesellschaft  Procedure and device for controlling the lateral dynamic attitude of a vehicle 
US5814718A (en)  19941104  19980929  Norsemeter A/S  Method and apparatus for measuring or controlling friction 
US5816666A (en)  19950721  19981006  Robert Bosch Gmbh  Process and apparatus for controlling the brake system of a vehicle 
US6015192A (en)  19960718  20000118  Nissan Motor Co., Ltd.  System for estimating vehicle body speed and road surface friction coefficient 
EP1000838A2 (en)  19981111  20000517  DaimlerChrysler AG  Method for controlling the lateral dynamics of a vehicle with front axle steering 
US6092415A (en)  19980225  20000725  Daimlerchrysler Ag  Method and device for monitoring the tire air pressure of the wheels of an automobile 
US6233505B1 (en)  19960502  20010515  Continental Teves Ag & Co., Ohg  Process for determining ideal vehicular performance 
WO2001036240A1 (en)  19991115  20010525  Newtech Mecatronic Inc.  Electronic braking device 
US6285280B1 (en)  20000626  20010904  Robert Bosch Corporation  Method for detecting a deflated tire on a vehicle 
WO2001076925A1 (en)  20000412  20011018  Nira Dynamics Ab  Adaptive filter model for motor vehicle sensor signals 
WO2001087647A1 (en)  20000412  20011122  Nira Dynamics Ab  Tire pressure estimation 
DE10128675A1 (en)  20000621  20020103  Koyo Seiko Co  Attitude control apparatus for stabilizing vehicle by controlling the braking forces, comprises angle sensor to determine a behavior index value corresponding to changes in vehicle behavior on basis of changes in steering angle 
US20020010537A1 (en)  20000405  20020124  Kabushiki Kaisha Toyota Chuo Kenkyusho  Tire parameter estimation device and road surface judgment device 
FR2816402A1 (en)  20001109  20020510  Continental Teves Ag & Co Ohg  Motor vehicle tyre wear detection or evaluation procedure uses measurements of vehicle performance and ambient parameters 
DE10156823A1 (en)  20001120  20020606  Toyota Motor Co Ltd  Device for estimating maximum road friction coefficient forms product of defined coefficient with ratios of reaction force and vertical load and of changes in reaction force and slip ratio 
US6550320B1 (en)  20000531  20030422  Continental Ag  System and method for predicting tire forces using tire deformation sensors 
EP1371534A1 (en)  20020613  20031217  Michelin Recherche et Technique S.A.  Vehicle stability control system using an invariant function characterising all type of tyres 
FR2840867A1 (en)  20020613  20031219  Michelin Soc Tech  Control for antiblocking brake system includes calculation based on tyre adherence using regression technique to determine optimum parameters 
US20040024514A1 (en)  20020613  20040205  Georges Levy  Automatic control method, usable in particular for maintaining the slip of a tire at an optimum level 
US20040049303A1 (en)  20020704  20040311  Georges Levy  Methods for estimation of tire wear 
US20040225423A1 (en)  20030507  20041111  Carlson Christopher R.  Determination of operational parameters of tires in vehicles from longitudinal stiffness and effective tire radius 
Patent Citations (37)
Publication number  Priority date  Publication date  Assignee  Title 

US3980346A (en)  19740710  19760914  Teldix Gmbh  Antilocking control system for simultaneous regulation of steered wheels or wheels on a diagonal of vehicle 
US4715662A (en)  19831216  19871229  Robert Bosch Gmbh  Method for determining an optimal slip value 
US4794538A (en)  19851008  19881227  Robert Bosch Gmbh  Method to control the operation of wheels of a vehicle to prevent slipping or skidding, and brake locking 
US5343918A (en)  19900517  19940906  The Goodyear Tire & Rubber Company  Tread for a pneumatic tire with differing tread stiffness regions 
US5402345A (en)  19900804  19950328  Robert Bosch Gmbh  Method for estimating speed of a braked vehicle 
DE4030724A1 (en)  19900928  19920402  Bosch Gmbh Robert  Vehicular antilock control system using inverse hydraulics model 
DE4218034A1 (en)  19920602  19931209  Porsche Ag  Measuring frictional connection potential of motor vehicle  involves measuring and smoothing vehicle parameters, e.g. speed and acceleration, and deriving vehicle state and road conditions 
US5409302A (en)  19921006  19950425  ThomsonCsf  Braking method and device, vehicle equipped with said device 
US5513907A (en)  19930622  19960507  Siemens Aktiengesellschaft  Method and circuit configuration for determining a frictional value 
DE4329745C1 (en)  19930903  19940721  Volkswagen Ag  Vehicle aquaplaning or skidding detection method 
DE4435448A1 (en)  19931013  19950420  Volkswagen Ag  Method for permanently determining the coefficient of adhesion of a carriageway 
US5814718A (en)  19941104  19980929  Norsemeter A/S  Method and apparatus for measuring or controlling friction 
EP0716948A2 (en)  19941214  19960619  Toyota Jidosha Kabushiki Kaisha  Dynamic behavior estimate system of automotive vehicle 
US5641212A (en)  19941214  19970624  Toyota Jidosha Kabushiki Kaisha  Dynamic behavior estimate system of automotive vehicle 
US5816666A (en)  19950721  19981006  Robert Bosch Gmbh  Process and apparatus for controlling the brake system of a vehicle 
US6233505B1 (en)  19960502  20010515  Continental Teves Ag & Co., Ohg  Process for determining ideal vehicular performance 
US6015192A (en)  19960718  20000118  Nissan Motor Co., Ltd.  System for estimating vehicle body speed and road surface friction coefficient 
EP0829401A2 (en)  19960913  19980318  Volkswagen Aktiengesellschaft  Procedure and device for controlling the lateral dynamic attitude of a vehicle 
US6092415A (en)  19980225  20000725  Daimlerchrysler Ag  Method and device for monitoring the tire air pressure of the wheels of an automobile 
EP1000838A2 (en)  19981111  20000517  DaimlerChrysler AG  Method for controlling the lateral dynamics of a vehicle with front axle steering 
US6449542B1 (en)  19981111  20020910  Daimlerchrysler Ag  Method for automatically controlling the lateral dynamics of a vehicle with frontaxle steering 
WO2001036240A1 (en)  19991115  20010525  Newtech Mecatronic Inc.  Electronic braking device 
US20020010537A1 (en)  20000405  20020124  Kabushiki Kaisha Toyota Chuo Kenkyusho  Tire parameter estimation device and road surface judgment device 
WO2001076925A1 (en)  20000412  20011018  Nira Dynamics Ab  Adaptive filter model for motor vehicle sensor signals 
WO2001087647A1 (en)  20000412  20011122  Nira Dynamics Ab  Tire pressure estimation 
US6550320B1 (en)  20000531  20030422  Continental Ag  System and method for predicting tire forces using tire deformation sensors 
DE10128675A1 (en)  20000621  20020103  Koyo Seiko Co  Attitude control apparatus for stabilizing vehicle by controlling the braking forces, comprises angle sensor to determine a behavior index value corresponding to changes in vehicle behavior on basis of changes in steering angle 
US6285280B1 (en)  20000626  20010904  Robert Bosch Corporation  Method for detecting a deflated tire on a vehicle 
FR2816402A1 (en)  20001109  20020510  Continental Teves Ag & Co Ohg  Motor vehicle tyre wear detection or evaluation procedure uses measurements of vehicle performance and ambient parameters 
DE10156823A1 (en)  20001120  20020606  Toyota Motor Co Ltd  Device for estimating maximum road friction coefficient forms product of defined coefficient with ratios of reaction force and vertical load and of changes in reaction force and slip ratio 
US20020111752A1 (en)  20001120  20020815  Toyota Jidosha Kabushiki Kaisha  Apparatus and method for estimating maximum road friction coefficient 
EP1371534A1 (en)  20020613  20031217  Michelin Recherche et Technique S.A.  Vehicle stability control system using an invariant function characterising all type of tyres 
FR2840867A1 (en)  20020613  20031219  Michelin Soc Tech  Control for antiblocking brake system includes calculation based on tyre adherence using regression technique to determine optimum parameters 
US20040024514A1 (en)  20020613  20040205  Georges Levy  Automatic control method, usable in particular for maintaining the slip of a tire at an optimum level 
US20040032165A1 (en)  20020613  20040219  Georges Levy  Automatic stability control system for a vehicle using an invariant characterizing any tire 
US20040049303A1 (en)  20020704  20040311  Georges Levy  Methods for estimation of tire wear 
US20040225423A1 (en)  20030507  20041111  Carlson Christopher R.  Determination of operational parameters of tires in vehicles from longitudinal stiffness and effective tire radius 
NonPatent Citations (3)
Title 

Grosch, K. A., "Determination of Friction and Wear Resistance of Tread CompoundsPart I: Wet Skid," Kautschuk and Gummi Kunststoffe, Jun. 1996, v49, No. 6, p. 432441 (Abstract). 
Sakai Tomotsugu "Investigation of Lambourn Wear Test Conditions to Evaluate Tire Wear Life," Toyota Motor Corp., Proceedings of the International Sessions JSME Spring Annual Meeting, 1996, vol. 73, p. 3334 (Abstract). 
Yamazaki Shun'ichi., "The Determination of Tire Parameter for Real Time Estimation of Tire and Road Friction," Jidosha Gijutsukai Koenkai Maezurishu, 1997, No. 971, p. 165168 (Abstract). 
Cited By (2)
Publication number  Priority date  Publication date  Assignee  Title 

US20070256484A1 (en) *  20041014  20071108  Etsujiro Imanishi  Tire Hil Simulator 
US7421890B2 (en) *  20041014  20080909  Kabushiki Kaisha Kobe Seiko Sho  Tire HIL simulator 
Also Published As
Publication number  Publication date  Type 

US20050187672A1 (en)  20050825  application 
CN1640702A (en)  20050720  application 
KR20050075717A (en)  20050721  application 
Similar Documents
Publication  Publication Date  Title 

US6351694B1 (en)  Method for robust estimation of road bank angle  
US6418369B2 (en)  Road surface friction coefficient estimating apparatus  
US6923514B1 (en)  Electronic brake control system  
US6198988B1 (en)  Method for detecting an erroneous direction of travel signal  
US6597980B2 (en)  Road friction coefficients estimating apparatus for vehicle  
US6604040B2 (en)  Apparatus and method for identifying tires and apparatus and method for evaluating road surface conditions  
US6015192A (en)  System for estimating vehicle body speed and road surface friction coefficient  
US20040019417A1 (en)  Wheel grip factor estimation apparatus  
US5551769A (en)  Method and system for split mu control for antilock brake systems  
US20040254703A1 (en)  Method and device for identifying and eliminating the risk of rollover  
US20020166373A1 (en)  Method and device for monitoring the instantaneous behaviour of a tyre during the running of a motor vehicle  
US20050055149A1 (en)  Wheel grip factor estimating apparatus and vehicle motion control apparatus  
US20090105921A1 (en)  Road surface condition estimating method, road surface condition estimating tire, road surface condition estimating apparatus, and vehicle control apparatus  
CN1439556A (en)  Control method for vehicle running stability  
US6611781B1 (en)  Method and device for determining a speed value  
US20110130974A1 (en)  Method and apparatus for road surface friction estimation based on the self aligning torque  
US6377885B2 (en)  Braking force control device  
JP2006034012A (en)  Method for operating slip ratio of wheel and method for controlling brake power of wheel  
Jiang et al.  An adaptive nonlinear filter approach to the vehicle velocity estimation for ABS  
US6678633B2 (en)  System and method for determining the height of the center of gravity of a vehicle  
US20100161194A1 (en)  System and method for active traction control of a vehicle  
JP2004130965A (en)  Road surface condition estimating device, and vehicle motion controller equipped with the same  
US6816799B2 (en)  Vehicle operating parameter determination system and method  
US6502014B1 (en)  Regulating circuit for regulating the driving stability of a motor vehicle using a motor vehicle reference model  
US20040002795A1 (en)  Apparatus and method for estimating a turning characteristic of a vehicle 
Legal Events
Date  Code  Title  Description 

AS  Assignment 
Owner name: MICHELIN RECHERCHE ET TECHNIQUE S.A., SWITZERLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FANGEAT, NICOLAS;LEVY, GEORGES;REEL/FRAME:016540/0030;SIGNING DATES FROM 20050321 TO 20050322 

CC  Certificate of correction  
REMI  Maintenance fee reminder mailed  
LAPS  Lapse for failure to pay maintenance fees  
FP  Expired due to failure to pay maintenance fee 
Effective date: 20110327 

AS  Assignment 
Owner name: COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, FR Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MICHELIN RECHERCHE ET TECHNIQUE S.A.;REEL/FRAME:044031/0249 Effective date: 20161219 